JPH0556599A - Structure for electric connection of small motor - Google Patents

Abstract

(57) [Abstract] [Purpose] With a simple structure, the force applied when press-connecting a connector for electrical connection to a control circuit, etc. is prevented from concentrating on the circuit board and motor terminals, and their damage is prevented. To improve durability and reliability. [Structure] In a small motor that has a circuit board connected to the motor terminals and has a connector on the side of the motor, a dust-proof cover or a motor case that covers the motor has a protrusion for supporting the back surface of the connector fixed to the circuit board. The stopper of is integrally formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric connection structure for a small motor such as a stepping motor.

[0002]

2. Description of the Related Art In a small motor such as a stepping motor, in order to electrically connect to an external control circuit,
In some cases, the circuit board connected to the motor terminal is arranged on the side surface of the motor. Further, as an electric connection structure of such a small motor, a structure may be adopted in which the circuit board and the control circuit and the like are detachably connected via a connector in order to facilitate assembly and handling. As a connector in this case, in general,
It is used that is composed of a connector head and a holder that are pressed into each other and connected. In the following description, these connector head and holder will be simply referred to as "connector" and "mating connector". The mating connector is also coupled to a flexible cable or lead wire from the control circuit. Further, for the purpose of protecting the exposed conductive portion of the electric connection structure such as the circuit board or preventing the contamination of the sensor such as the encoder, the peripheral surface thereof may be covered with a dust cover.

[0003]

However, in the conventional small-sized motor, when the circuit board and the control circuit are connected by the connector, the connector is simply fixed to the circuit board by soldering or the like. Therefore, when connecting the flexible cable from the control circuit or the mating connector that is connected to the lead wire, force in the insertion direction may be applied, which may cause deformation or damage to the connection part between the circuit board and the motor terminal. It was

The present invention has been made in view of the above technical problems, and an object of the present invention is to have a simple structure and a force applied at the time of connecting a connector is concentrated on a portion of a circuit board and a motor terminal. It is an object of the present invention to provide an electrical connection structure for a small motor that can improve durability and reliability by eliminating the above problems and preventing their damage.

[0005]

According to the present invention, in a small motor in which a circuit board for connecting a motor terminal is provided on a side surface of the motor, a dustproof cover for covering the motor supports a back surface of a connector fixed to the circuit board. By integrally forming a protrusion-shaped stopper for
The above object is achieved. Further, another invention is
In a small motor in which a circuit board for connecting a motor terminal is provided on the side surface of the motor, a projection-shaped stopper for supporting the back surface of the connector fixed to the circuit board is integrally formed in the motor case. By doing so, the above object is achieved.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view showing a structural example of a small motor having an embodiment of an electrical connection structure to which the present invention is applied.
In FIG. 1, a bearing housing 11 is formed at the center of a drum-shaped motor case 10 with one end open.
A mounting plate 12 is fixed to the open end surface of the motor case 10 by fixing means such as caulking 13, and another bearing housing 14 is formed at the motor shaft center portion of the mounting plate 12. The mounting plate 12 also serves as an end plate that seals the open end surface of the motor case 10. A motor shaft 17 is supported by bearings 15 and 16 press-fitted and fixed in the bearing housings 11 and 14, respectively.

A rotor 18 is press-fitted and fixed at a position of the motor shaft 17 in the motor case 10. The rotor 18 is magnetized to the N and S poles at a predetermined pitch in the circumferential direction on the outer peripheral portion of the rotor 18. A magnet 19 is formed. Inside the motor formed by the motor case 10 and the mounting plate 12, two stator units 5 facing the rotor magnet 19 with a gap are provided.
0 and 60 are arranged side by side in the axial direction. Each of the stator units 50 and 60 has a structure in which the exciting coils 20 and 21 are housed between the inner and outer yokes having pole teeth, and constitutes the exciting phase of the motor. It has two excitation phases.

In the illustrated example, the first-phase outer yoke 22 is fixed to the end surface of the motor case 10, and the first-phase inner yoke 23 and the second-phase inner yoke 24 are joined back to back. The outer yoke 25 of the second phase is the mounting plate 1
It is fixed at 2. The first phase outer yoke 22
The second-phase outer yoke 25 and the second-phase outer yoke 25 may be integrally formed with the motor case 10 and the mounting plate 12, respectively. Thus, the first inner and outer yokes 2
By mounting the first exciting coil 20 wound around the bobbin 26 inside the second and second members 23, the first-phase stator unit 50 is configured, and the second inner and outer yokes 2 are formed.
By mounting the second exciting coil 21 wound around the bobbin 27 inside the Nos. 4 and 25, the second-phase stator unit 60 is configured.

Each of the yokes 22, 23, 24, 25 is provided with a plurality of pole teeth formed at a predetermined pitch in the circumferential direction so as to face the rotor magnet 19 with a predetermined gap. The bobbins 26, 2
7 is made of, for example, an insulating material such as plastic, and portions 26A and 27A thereof are exposed from the side surface cutout portion 38 of the motor case 10. The exposed portions are connected to the excitation coils 20 and 21, respectively. Motor terminals 28, 29
(4 or 6 in total) are fixed so as to project to the outside. A rotational force extracting means 30 such as a pulley is fixed to the output side projection of the motor shaft 17.

An encoder 31 for detecting the angle and speed of motor rotation is attached to the outside of the motor case 10 on the side opposite to the output side of the motor.
The encoder 31 includes a coded disc (slit disc in the illustrated example) 3 positioned and fixed to the motor shaft 17.
2 and a sensor (photo interrupter in the illustrated example) 33 positioned and fixed on the outer surface of the motor case 10. The sensor 33 is arranged on the same side as the motor terminals 28 and 29 connected to the excitation coils 20 and 21, and the motor terminals connected to the sensor 33 (for example, a total of 4 for power supply and 4 for signal). (Comprising encoder terminals of a book) 34 is the motor terminal 2
It projects substantially in the same direction as 8 and 29.

Each of the motor terminals 28, 29, 34 (a total of 8) projecting to the substantially same side in the circumferential direction of the motor case 10.
The book or ten pieces) are formed of a conductive rod-shaped or plate-shaped metal having a predetermined rigidity. Therefore, the circuit board 35 is fixed to the tip portions of the motor terminals 28, 29, 34 by soldering or the like. This circuit board 35
Is for connecting each motor terminal 28, 29, 34 to an external control circuit, and a circuit pattern connected to each motor terminal 28, 29, 34 is formed on the circuit board 35. The circuit board 35 is arranged on the side surface of the motor, that is, outside the peripheral surface of the motor case 10. Further, the motor case 10 has a cover (dustproof cover) 3 for covering the motor case 10, the encoder 31, and the circuit board 35.
6 is detachably attached. The cover 36 is for preventing dust from adhering to the coded disc 32 and the circuit board 35, and for preventing dust from entering the motor case 10. For example, insulating material such as plastic is used. It is made of molded products (molds).

FIG. 2 is a perspective view showing the motor case 10 and the circuit board 35 in FIG. 1, FIG. 3 is a perspective view showing the cover 36 in FIG. 1, and FIG. 4 is a line 4--in FIG. FIG. 4 is a transverse sectional view taken along line 4 of FIG. 2 and 4, a connector 41 for circuit connection is fixed to the lower surface of one end of the circuit board 35. Note that reference numeral 42 in FIG. 2 denotes a mating connector, and this mating connector 42 is coupled to the tip portion of the flexible cable 43 from the control circuit. 3 and 4, the cover 36 includes:
A bulge portion 44 for covering the circuit board 35 is integrally formed.

Therefore, the bulging portion 44 of the cover 36
A protrusion 45 for substantially abutting the rear surface of the connector 41 of the circuit board 36 and supporting the connector 41 from the rear surface is integrally formed inside. Thus, the electrical connection structure is provided in which the projection-shaped stopper 45 for supporting the back surface of the connector 41 fixed to the circuit board 35 is integrally formed on the dust-proof cover 36 that covers the motor.

As shown in FIGS. 2 and 3, notches for detachably mounting the cover 36 are provided at positions (two locations) in the opening end of the motor case 10 that face each other in the diametrical direction. 46, on the other hand, at positions corresponding to the notches 46 of the cover 36, elastically displaceable locking portions 47 (two positions) for locking (patching) the respective notches 46 are formed. Has been done. That is, the cover 3
6 is detachably positioned and fixed to the motor case 10 by the notch 46 and the locking portion 47.

FIG. 5 is a transverse sectional view of a small motor having another embodiment of the electrical connection structure to which the present invention is applied, corresponding to FIG. 4, and FIG. 6 is a perspective view of the motor case 10 in FIG. .. 5 and 6, the motor case 10
A protrusion-shaped stopper 51 for contacting and supporting the rear surface of the connector 41 fixed to the circuit board 35 is formed integrally with the motor case 10 on the peripheral surface of the circuit board 35. Has been done. In the illustrated example, the stopper 51 is formed by a cut-and-raised protrusion that is formed by cutting and raising a part (two places) of the motor case 10 to the outside, but this is a separate member on the peripheral surface of the motor case 10. May be a protrusion formed by being fixed by welding or adhesion.

The embodiment of FIGS. 5 and 6 shows a connector 4
Stopper 51 for supporting 1 motor case 1
0 differs from the embodiment of FIGS. 1 to 4 in that it is provided, and the other parts have substantially the same structure. Corresponding parts are designated by the same reference numerals, and detailed description thereof will be omitted. ..

According to each of the embodiments described above, the motor terminals 28, 2 protruding from the side surface of the motor case 10.
In a small motor having a structure in which a connector 41 for electrical connection is fixed to a circuit board 35 fixed and supported to 9, 34, a projection for supporting the back surface of the connector 41 on a dust cover 36 for covering the motor or the motor case 10. Since the stoppers 45 or 51 are integrally formed, even if a pressing force is applied when the mating connector 42 is press-fitted (press-inserted), this force is concentrated on the circuit board 35 and the motor terminals 28, 29, 34. Therefore, the effect of reinforcing the joint between the circuit board 35 and the motor terminals 28, 29, 34 can be obtained with a simple structure, and the deformation and damage of the joint can be prevented to prevent the motor from being damaged. It has become possible to improve durability and reliability.

[0018]

As is apparent from the above description, according to the present invention, in a small motor in which a circuit board for connecting motor terminals is provided on a side surface of the motor, a dust cover for covering the motor is fixed to the circuit board. In addition, since the projection-shaped stopper for supporting the back surface of the connector is integrally formed, the force applied when the connector is coupled is not concentrated on the circuit board and the motor terminal with a simple structure. An electrical connection structure for a small motor is provided that can improve durability and reliability by preventing their damage.

According to another aspect of the present invention, in a small motor in which a circuit board for connecting a motor terminal is provided on a side surface of the motor, a motor case supports a back surface of a connector fixed to the circuit board. Since the protrusion-shaped stopper is integrally formed, the force applied when connecting the connector is prevented from concentrating on the circuit board and motor terminal parts with a simple structure, and by preventing them from being damaged. An electrical connection structure for a small motor is provided that can improve durability and reliability.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a configuration example of a small motor provided with an electrical connection structure according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a motor case and a circuit board in FIG.

3 is a perspective view showing a motor cover in FIG. 1. FIG.

4 is a cross-sectional view taken along the line 4-4 in FIG.

FIG. 5 is a cross-sectional view showing a configuration example of a small motor having an electrical connection structure according to another embodiment of the present invention.

FIG. 6 is a perspective view showing a single motor case in FIG.

[Explanation of symbols]

 10 motor case 17 motor shaft 18 rotor 19 rotor magnet 20 exciting coil 21 exciting coil 26 bobbin 27 bobbin 28 motor terminal 29 motor terminal 31 encoder 33 sensor 34 motor terminal 35 circuit board 36 cover 38 motor case notch 41 connector 42 mating Connector 43 Flexible cable 44 Swelling portion 45 Stopper (projection of cover) 50 First phase stator unit 51 Stopper (projection of motor case) 60 Second phase stator unit

Claims (2)

[Claims] 1. In a small motor having a circuit board for connecting a motor terminal on a side surface of the motor, a dust-proof cover for covering the motor is provided with a protruding stopper for supporting a rear surface of a connector fixed to the circuit board. Electric connection structure for small motors, characterized by being formed integrally. 2. In a small motor in which a circuit board for connecting a motor terminal is provided on a side surface of the motor, a protruding stopper for supporting a back surface of a connector fixed to the circuit board is integrally formed in the motor case. An electric connection structure for a small motor characterized by being formed.